1. Technical Field
The present invention relates to an electronic timepiece provided with a solar panel.
2. Description of Related Art
Electronic equipment such as an electronic clock is disclosed in the related art (for example, see JP-A-2002-186186). The electronic equipment described in JP-A-2002-186186 is configured to prohibit display when a power voltage is lowered and reaches a first voltage, perform an initializing process when the power voltage reaches a second voltage lower than the first voltage, and then restart the display when the voltage is restored and reaches a third voltage (>first voltage).
Electronic equipment with a power generating apparatus is also disclosed in the related art (for example, see Japanese Patent No.3738334). The electronic equipment described in Japanese Patent No.3738334 is provided with an all clear circuit configured to start an output of an all clear signal to an LSI when the power voltage is at a voltage level slightly higher than a lower limit of an LSI action for a timepiece, and then, after the power voltage has reached an oscillation start voltage higher than the lower limit of the action voltage, continue the output of the all clear signal until a certain period has elapsed.
Incidentally, in the electronic timepiece in the related art, an illuminance of a solar panel is low (for example, 500 lx), and if a start of oscillation and a time-of-day display are performed simultaneously from immediately after a release of reset of a CPU when restoring a secondary battery from a vacant state to a completely charged state in a state in which a generated current in the solar panel is low, a consumed current required for activation may exceed the generated current of the solar panel. Therefore, in the electronic timepiece, there may be a case where actions of “start oscillation and release CPU reset→lowering of battery voltage→reset CPU→increase in battery voltage by power generation→start oscillation and release CPU reset→lowering of battery voltage . . . ” are repeated and hence the secondary battery cannot be restored normally and hence cannot be charged.